A method for preparing lithium-doped manganese dioxide-carbon cloth composite containing oxygen defects from waste lithium manganate material and application

Abstract

This invention discloses a method and application for preparing oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composites from recycled waste lithium manganese oxide materials. The method involves reducing and leaching waste lithium manganese oxide cathode powder in a mixed solution of C2H4O2 and H2O2 to obtain a lithium manganese oxide leachate. The pH of the leachate is adjusted with ammonia water and used as an electrodeposition stock solution. Electrochemical deposition is performed on hydrophilic carbon cloth using constant voltage electrodeposition to obtain a MnO2-carbon cloth composite. The MnO2-carbon cloth composite is then used as an ion sieve and immersed in the electrodeposition solution for a period of time to obtain a lithium-ion-doped MnO2-carbon cloth composite. The lithium-ion-doped MnO2-carbon cloth composite is calcined in a muffle furnace to obtain an oxygen-defect-containing lithium-ion-doped MnO2-carbon cloth composite, which is used as a cathode material for zinc-ion batteries. This composite exhibits excellent zinc storage performance, with a specific capacity as high as 120 mAh / g after 1200 charge-discharge cycles at a current density of 1 A / g. Under ultra-high current density (A / g), the specific capacity remains stable at 75 mAh / g after 5000 charge-discharge cycles.

Description

Technical Field

[0001] This invention belongs to the field of zinc-ion battery materials and the field of recycling of waste battery materials. In particular, it relates to a method and application for the regeneration of waste lithium manganese oxide materials to prepare lithium-doped manganese dioxide-carbon cloth composites with oxygen defects. Background Technology

[0002] Currently, in response to the energy crisis, countries are promoting the application of new energy electric vehicles. Lithium-ion batteries have become the main power choice for new energy vehicles. As one of the three major types of lithium-ion batteries, lithium manganese oxide batteries are seeing an increasing number of retired batteries each year. How to achieve high-value recycling and reuse of waste lithium manganese oxide battery materials is urgently needed. Furthermore, compared to lithium-ion batteries, zinc-ion batteries have advantages such as low cost, high safety, abundant resources, and environmental friendliness, and have received considerable attention in recent years. At present, based on the advantages of manganese-based zinc-ion battery cathode materials being abundant in nature, having diverse crystal structures, and the absence of combustion risks with aqueous electrolytes, the development of manganese-based zinc-ion batteries in large-scale energy storage systems has been further promoted. However, zinc-ion batteries with MnO2 as the cathode suffer from poor material conductivity and the loss of Mn content in the manganese-based material during charge-discharge cycles. 2+ Problems such as dissolution and disproportionation reactions, and instability of the layered structure leading to structural collapse, severely limit the performance of zinc-ion cathode materials. Therefore, designing and modifying manganese-based zinc-ion cathode materials to improve the cycle and storage performance of batteries has become a research hotspot for zinc-ion cathode materials.

[0003] Among various zinc-ion cathode materials, manganese is favored by researchers due to its abundant reserves, safety, environmental friendliness, and diverse crystal structures. However, manganese-based materials also suffer from poor conductivity and structural collapse and dissolution during charge and discharge, leading to reduced zinc storage performance of MnO2 in zinc-ion batteries. Therefore, this patent synthesizes a lithium-ion-doped manganese dioxide carbon cloth composite material through electrodeposition, further enhancing its conductivity. Furthermore, calcination can further construct oxygen defects in the material, increasing zinc storage sites. However, the strategy of using electrodeposition combined with calcination to prepare oxygen-defect-containing lithium-ion-doped manganese dioxide zinc storage materials has not been reported in the literature.

[0004] This invention utilizes carbon cloth with good conductivity as a carrier for oxygen-deficient lithium-ion doped manganese dioxide, and increases the oxygen vacancies in the material through calcination to prepare an oxygen-deficient lithium-doped manganese dioxide-carbon cloth composite material from recycled waste lithium manganese oxide. The difference between this method and conventional methods is as follows: First, by combining organic acid acetic acid and a reducing agent, the cathode material of waste lithium-ion batteries is directly leached and used as an electrolyte for electrodeposition of manganese dioxide. This method can both recycle waste lithium-ion batteries and serve as raw material for zinc-ion batteries. Second, carbon cloth is used as a current collector, and active materials are loaded onto it through electrodeposition. During battery assembly, it is not necessary to use a binder to bond the active material to the current collector. The material synthesized in this method is uniformly distributed on the surface of the carbon cloth, effectively suppressing structural changes during charging and discharging. Third, the manganese dioxide-carbon cloth composite obtained by electrodeposition is used as an ion sieve in the original leaching solution to adsorb lithium ions, resulting in lithium-ion-doped manganese dioxide-carbon cloth composites. This method not only achieves the purpose of recycling valuable metals from waste batteries but also produces high-performance zinc-ion cathode materials, showing promising application prospects. Summary of the Invention

[0005] The purpose of this invention is to provide a method and application for preparing oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composites by regenerating waste lithium manganese oxide materials. The method is simple to operate, uses widely available raw materials, is low in cost, and is environmentally friendly.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composites from recycled waste lithium manganese oxide materials as positive electrodes for aqueous zinc-ion batteries includes the following steps: (1) Take 1-1000 g of waste lithium manganese oxide material, stir and leach it with 2-100 mL of a mixed solution of 1-10 M C2H4O2 and 1.5-100 mL of 30wt% H2O2, stir in a magnetic stirrer at 60 °C for 0.5-1 h to obtain lithium manganese oxide leaching solution; (2) Adjust the pH of the lithium manganese oxide leaching solution obtained in step (1) to 5-7 with ammonia water to obtain a pH 5-7 solution for later use; (3) The pH 5~7 solution obtained in step (2) was used as the electrodeposition stock solution and electrochemically deposited on the hydrophilic carbon cloth. The MnO2-carbon cloth composite was obtained by constant voltage electrodeposition. (4) The MnO2-carbon cloth composite obtained in step (3) is used as an ion sieve and soaked in the pH 5~7 solution obtained in step (2) for a period of time (1-10 h) to obtain lithium ion doped MnO2-carbon cloth composite. (5) The lithium-ion-doped MnO2-carbon cloth composite obtained in step (4) is calcined in a muffle furnace to obtain an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. (6) The lithium-doped manganese dioxide-carbon cloth composite with oxygen defects was used as the positive electrode of an aqueous zinc-ion battery, and its zinc storage performance was tested.

[0007] The aforementioned waste lithium manganese oxide material refers to the lithium manganese oxide cathode powder separated after disassembling waste lithium manganese oxide batteries.

[0008] The hydrophilic treatment described in step (3) above involves using a platinum electrode as the auxiliary electrode and Ag / AgCl as the reference electrode, and performing 2-5 cyclic voltammetric tests on the carbon cloth in a 2 mol / L H2SO4 solution at a scan rate of 20 mV / s; the electrodeposition voltage is 1 V, the electrodeposition time is 300 s, and the solution temperature during electrodeposition is 35-60 ℃.

[0009] The calcination conditions in the muffle furnace described in step (5) above are 350-450 ℃ and the calcination time is 1-3 h.

[0010] The MnO2-carbon cloth composite described in step (3) above serves as an ion sieve, further embedding lithium ions, and constructing oxygen defects after calcination.

[0011] The present invention describes a method for preparing a lithium-doped manganese dioxide-carbon cloth composite material containing oxygen defects by regenerating waste lithium manganese oxide material.

[0012] The present invention relates to the application of a method for preparing oxygen-deficient lithium-doped manganese dioxide-carbon cloth composite material by recycling waste lithium manganese oxide material. The method is characterized in that the oxygen-deficient lithium-doped manganese dioxide-carbon cloth composite material is used as the positive electrode of a zinc-ion battery, a zinc sheet is used as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 are used as electrolytes to assemble a button-type 2025 battery.

[0013] Specifically, the technical solution adopted in this invention is as follows: A method for preparing oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composites from recycled waste lithium manganese oxide materials as positive electrodes for aqueous zinc-ion batteries includes the following steps: (1) Take 1-1000 g of waste lithium manganese oxide material, stir and leach it with 2-100 mL of a mixed solution of 1-10 M C2H4O2 and 1.5-100 mL of 30wt% H2O2, stir in a magnetic stirrer at 60 °C for 0.5-1 h to obtain lithium manganese oxide leaching solution; (2) Adjust the pH of the lithium manganese oxide leaching solution obtained in step (1) to 5-7 with ammonia water to obtain a pH 5-7 solution for later use; (3) The pH 5~7 solution obtained in step (2) was used as the electrodeposition stock solution and electrochemically deposited on the hydrophilic carbon cloth. The MnO2-carbon cloth composite was obtained by constant voltage electrodeposition. (4) The MnO2-carbon cloth composite obtained in step (3) is used as an ion sieve and soaked in the pH 5~7 solution obtained in step (2) for a period of time (1-10 h) to obtain lithium ion doped MnO2-carbon cloth composite. (5) The lithium-ion-doped MnO2-carbon cloth composite obtained in step (4) is calcined in a muffle furnace to obtain an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. (6) The lithium-doped manganese dioxide-carbon cloth composite with oxygen defects was used as the positive electrode of an aqueous zinc-ion battery, and its zinc storage performance was tested.

[0014] The aforementioned waste lithium manganese oxide material refers to the lithium manganese oxide cathode powder separated after disassembling waste lithium manganese oxide batteries.

[0015] The hydrophilic treatment described in step (3) above involves using a platinum electrode as the auxiliary electrode and Ag / AgCl as the reference electrode, and performing 2-5 cyclic voltammetric tests on the carbon cloth in a 2 mol / L H2SO4 solution at a scan rate of 20 mV / s; the electrodeposition voltage is 1 V, the electrodeposition time is 300 s, and the solution temperature during electrodeposition is 35-60 ℃.

[0016] The calcination conditions in the muffle furnace described in step (5) above are 350-450 ℃ and the calcination time is 1-3 h.

[0017] The MnO2-carbon cloth composite described in step (3) above serves as an ion sieve, further embedding lithium ions, and constructing oxygen defects after calcination.

[0018] The present invention describes a method for preparing a lithium-doped manganese dioxide-carbon cloth composite material containing oxygen defects by regenerating waste lithium manganese oxide material.

[0019] The present invention relates to the application of a method for preparing oxygen-deficient lithium-doped manganese dioxide-carbon cloth composite material by recycling waste lithium manganese oxide material. The method is characterized in that the oxygen-deficient lithium-doped manganese dioxide-carbon cloth composite material is used as the positive electrode of a zinc-ion battery, a zinc sheet is used as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 are used as electrolytes to assemble a button-type 2025 battery.

[0020] Specifically, the technical solution adopted by the present invention is as follows: 1) A certain mass of waste lithium manganese oxide battery powder (1-100 g), 2-20 mL of C2H4O2 (1-10 M) and 1.5-20 mL of 30% H2O2 mixed solution are stirred and leached. The temperature is heated to 60 ℃ and magnetically stirred for a certain time (0.5~1 h) to obtain a lithium manganese oxide leaching solution for later use. 2) Adjust the pH of the completely leached solution from step 1) to 5-7 with ammonia water. Use the solution as the electrodeposition stock solution and perform electrochemical deposition on the hydrophilic carbon cloth. Obtain MnO2-carbon cloth composite by constant voltage electrodeposition; 3) Use the MnO2-carbon cloth composite obtained in step 2) as an ion sieve and soak it in the electrodeposition solution for a period of time (1-10 h) to obtain lithium ion-doped MnO2-carbon cloth composite.

[0021] 4) The lithium-ion-doped MnO2-carbon cloth composite from step 3) is calcined in a muffle furnace at 350-450 °C for 1-3 h. This yields an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite, which can be used as a cathode material for zinc-ion batteries.

[0022] 5) The lithium-ion-doped MnO2-carbon cloth composite was used as the positive electrode of an aqueous zinc-ion battery, and its zinc storage performance was tested.

[0023] The zinc storage performance test mentioned in step (5) above includes: the application of the waste lithium manganese oxide material regeneration preparation of oxygen-defect lithium-doped manganese dioxide-carbon cloth composite according to claim 1, characterized in that the electrochemical test mentioned in step (5) includes: the oxygen-defect lithium-doped manganese dioxide-carbon cloth composite as the positive electrode of the zinc-ion battery, the zinc sheet as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 as the electrolyte to assemble a button-type 2025 battery.

[0024] Compared with existing technologies, the present invention has the following specific advantages: 1) The amount of waste lithium-ion cathode materials is increasing. If they are not effectively recycled, they will not only pollute the environment but also waste resources. This patent prepares a zinc-ion battery cathode material with excellent electrochemical performance by leaching waste lithium manganese oxide cathode powder with organic acid and simultaneously recovering lithium and manganese metal elements through electrodeposition and ion doping.

[0025] 2) Lithium-ion doping increases the interlayer spacing of MnO2 crystal materials, preventing structural collapse during cycling and improving cycle life; introducing oxygen defects into the cathode material can significantly reduce the energy barrier for the migration and diffusion of zinc ions in the cathode material, promoting zinc rate performance.

[0026] 3) The zinc-ion battery cathode prepared by this invention can be obtained by electrodeposition, which is simple to operate, low in cost, and environmentally friendly.

[0027] 4) As a positive electrode for zinc-ion batteries, it exhibits excellent electrochemical performance. Within a voltage range of 0.7-1.8 V, the specific capacity reaches 120 mAh / g after 1200 charge-discharge cycles at a current density of 1 A / g; and the specific capacity remains stable at 75 mAh / g after 5000 charge-discharge cycles at a high current density of 10 A / g. Attached Figure Description

[0028] Figure 1 This is the XRD pattern of the oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite obtained in Example 1.

[0029] Figure 2 This is a SEM image of the oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite obtained in Example 1.

[0030] Figure 3 This is a graph showing the cycling performance of the oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite obtained in Example 1 as a cathode material for zinc-ion batteries at a current density of 1 A / g.

[0031] Figure 4 The charge-discharge curves of the oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite obtained in Example 1 as the positive electrode material of a zinc-ion battery are shown at a current density of 1 A / g.

[0032] Figure 5 This is a graph showing the cycling performance of the oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite obtained in Example 1 as a cathode material for zinc-ion batteries at an ultra-high current density of 10 A / g. Implementation Example 1

[0033] 1 g of waste lithium manganese oxide cathode material (in this embodiment, the lithium manganese oxide cathode powder separated after disassembling a waste lithium manganese oxide battery) was mixed with 2 mL of 1 M C2H4O2 and 1.5 mL of 30 wt% H2O2 and stirred at 60 °C for 1 h in a magnetic stirrer. The pH was adjusted to 5-7 with ammonia water to serve as the electrodeposition stock solution. The functionalization treatment of carbon cloth was carried out in 2 mol / L H2SO4 solution, using a platinum electrode as the auxiliary electrode and Ag / AgCl as the reference electrode, and two cyclic voltammetric scans were performed on the carbon cloth at a scan rate of 20 mV / s. First, a CV scan was performed with a lower potential limit of 0.9 V and an upper potential limit of 2.5 V to prepare hydrophilic carbon cloth. Using the hydrophilic carbon cloth as the working electrode, a platinum electrode as the counter electrode, and Ag / AgCl as the reference electrode, a constant voltage of 1 V was applied, and the electrodeposition time was set to 300 s. After electrodeposition, the carbon cloth was immersed in the electrodeposition solution for 4 h to obtain a lithium-ion-doped MnO2-carbon cloth composite. This composite was then calcined in a muffle furnace at 350 ℃ for 2 h to obtain an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. When this material was used as the positive electrode in a zinc-ion battery, a zinc sheet was used as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 were used as the electrolyte to assemble a button-type 2025 battery. Battery performance was tested; all assemblies were performed in a normal environment outside of gloves, and cycle performance was also tested.

[0034] Figure 1 The image shows the XRD pattern of the oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. Matching the image reveals that the crystal phase of the obtained sample is MnO2. (Attached) Figure 2 The image shows a SEM image of the oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite, revealing a nanorod-like structure grown on the carbon cloth. When this composite is used as an electrode material for zinc-ion batteries, it exhibits a specific capacity of up to 120 mAh / g after 1200 charge-discharge cycles within a voltage range of 0.7–1.8 V and a current density of 1 A / g. Figure 3 The corresponding charge / discharge curves are as follows: Figure 4 As can be seen from the figure, except for the first cycle, the charge-discharge curves of the second and third cycles are basically the same, indicating that the material has excellent cycle stability. Figure 5 The graph shows the cycling performance of the electrode after 5000 cycles at a current density of 10 A / g. Its specific capacity is stable at 75 mAh / g, indicating that the material has excellent long-cycle performance. Example 2

[0035] 1 g of waste lithium manganese oxide cathode material (in this embodiment, the lithium manganese oxide cathode powder separated after disassembling a waste lithium manganese oxide battery) was mixed with 2 mL of 1 M C2H4O2 and 1.5 mL of 30 wt% H2O2 and stirred in a magnetic stirrer at 60 °C for 1 h. The pH was adjusted to 7 with ammonia water to serve as the electrodeposition stock solution. The functionalization treatment of carbon cloth was carried out in a 2 mol / L H2SO4 solution, using a platinum electrode as the auxiliary electrode and Ag / AgCl as the reference electrode, and two cyclic voltammetric scans were performed on the carbon cloth at a scan rate of 20 mV / s. First, a CV scan was performed with a lower potential limit of 0.9 V and an upper potential limit of 2.5 V to prepare hydrophilic carbon cloth. Using the hydrophilic carbon cloth as the working electrode, a platinum electrode as the counter electrode, and Ag / AgCl as the reference electrode, a constant voltage of 1 V was applied, and the electrodeposition time was set to 300 s. After electrodeposition, the carbon cloth was immersed in the electrodeposition solution for 4 h to obtain a lithium-ion-doped MnO2-carbon cloth composite. This composite was then calcined in a muffle furnace at 350 ℃ for 2 h to obtain an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. The oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite prepared in this embodiment was used as the positive electrode of a zinc-ion battery, with a zinc sheet as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 as the electrolyte to assemble a button-type 2025 battery. Battery performance was tested; all assembly was performed in a normal environment outside of gloves, and cycle performance was also tested. Example 3

[0036] 1000 g of waste lithium manganese oxide cathode material (in this embodiment, the lithium manganese oxide cathode powder separated after disassembling a waste lithium manganese oxide battery) was mixed with 100 mL of 3 M C2H4O2 and 100 mL of 30 wt% H2O2 and stirred at 60 °C for 1 h in a magnetic stirrer. The pH was adjusted to 5-7 with ammonia water to serve as the electrodeposition stock solution. The functionalization treatment of carbon cloth was carried out in 2 mol / L H2SO4 solution, using a platinum electrode as the auxiliary electrode and Ag / AgCl as the reference electrode. Five cyclic voltammetric scans were performed on the carbon cloth at a scan rate of 20 mV / s. First, a CV scan was performed with a lower potential limit of 0.9 V and an upper potential limit of 2.5 V to prepare hydrophilic carbon cloth. Using the hydrophilic carbon cloth as the working electrode, a platinum electrode as the counter electrode, and Ag / AgCl as the reference electrode, a constant voltage of 1 V was applied, and the electrodeposition time was set to 300 s. After electrodeposition, the carbon cloth was immersed in the electrodeposition solution for 8 h to obtain a lithium-ion-doped MnO2-carbon cloth composite. This composite was then calcined in a muffle furnace at 450 ℃ for 3 h to obtain an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. The oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite prepared in this embodiment was used as the positive electrode of a zinc-ion battery, with a zinc sheet as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 as the electrolyte to assemble a button-type 2025 battery. Battery performance was tested; all assembly was performed in a normal environment outside of gloves, and cycle performance was also tested. Example 4

[0037] 100 g of waste lithium manganese oxide cathode material (in this embodiment, the lithium manganese oxide cathode powder separated after disassembling a waste lithium manganese oxide battery) was mixed with 10 mL of 3 M C2H4O2 and 10 mL of 30 wt% H2O2 and stirred in a magnetic stirrer at 60 °C for 1 h. The pH was adjusted to 7 with ammonia water to serve as the electrodeposition stock solution. The functionalization treatment of carbon cloth was carried out in a 2 mol / L H2SO4 solution. A platinum electrode was used as the auxiliary electrode and Ag / AgCl was used as the reference electrode. Two cyclic voltammetric scans were performed on the carbon cloth at a scan rate of 20 mV / s. First, a CV scan was performed with a lower potential limit of 0.9 V and an upper potential limit of 2.5 V to prepare hydrophilic carbon cloth. Using the hydrophilic carbon cloth as the working electrode, a platinum electrode as the counter electrode, and Ag / AgCl as the reference electrode, a constant voltage of 1 V was applied, and the electrodeposition time was set to 300 s. After electrodeposition, the carbon cloth was immersed in the electrodeposition solution for 8 h to obtain a lithium-ion-doped MnO2-carbon cloth composite. This composite was then calcined in a muffle furnace at 400 ℃ for 2 h to obtain an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. The oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite prepared in this embodiment was used as the positive electrode of a zinc-ion battery, with a zinc sheet as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 as the electrolyte to assemble a button-type 2025 battery. Battery performance was tested; all assembly was performed in a normal environment outside of gloves, and cycle performance was also tested.

[0038] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A method for preparing oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite material from recycled waste lithium manganese oxide material as the positive electrode of an aqueous zinc-ion battery, comprising the following steps: (1) Take 1-1000 g of waste lithium manganese oxide material, stir and leach it with 2-100 mL of a mixed solution of 1-10 M C2H4O2 and 1.5-100 mL of 30wt% H2O2, stir in a magnetic stirrer at 60 °C for 0.5-1 h to obtain lithium manganese oxide leaching solution; (2) Adjust the pH of the lithium manganese oxide leaching solution obtained in step (1) to 5-7 with ammonia water to obtain a pH 5-7 solution for later use; (3) The pH 5~7 solution obtained in step (2) was used as the electrodeposition stock solution and electrochemically deposited on the hydrophilic carbon cloth. The MnO2-carbon cloth composite was obtained by constant voltage electrodeposition. (4) The MnO2-carbon cloth composite obtained in step (3) is used as an ion sieve and soaked in the pH 5~7 solution obtained in step (2) for a period of time (1-10 h) to obtain lithium ion doped MnO2-carbon cloth composite. (5) The lithium-ion-doped MnO2-carbon cloth composite obtained in step (4) is calcined in a muffle furnace to obtain an oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite. (6) The lithium-doped manganese dioxide-carbon cloth composite with oxygen defects was used as the positive electrode of an aqueous zinc-ion battery, and its zinc storage performance was tested.

2. The method according to claim 1, characterized in that... Waste lithium manganese oxide material refers to the lithium manganese oxide cathode powder separated after disassembling waste lithium manganese oxide batteries.

3. The method according to claim 1, characterized in that... The hydrophilic treatment in step (3) involves using a platinum electrode as the auxiliary electrode and Ag / AgCl as the reference electrode to perform 2-5 cyclic voltammetry tests on the carbon cloth in a 2 mol / L H2SO4 solution at a scan rate of 20 mV / s; the electrodeposition voltage is 1 V, the electrodeposition time is 300 s, and the solution temperature during electrodeposition is 35-60 ℃.

4. The method according to claim 1, characterized in that... The calcination conditions in step (5) in the muffle furnace are 350-450 °C and the calcination time is 1-3 h.

5. The method according to claim 1, characterized in that... The MnO2-carbon cloth composite described in step (3) serves as an ion sieve, further embedding lithium ions, and constructing oxygen defects through calcination.

6. A lithium-doped manganese dioxide-carbon cloth composite material containing oxygen defects prepared by the method described in any one of claims 1-5 through the regeneration of waste lithium manganese oxide material.

7. The application of the method for preparing oxygen-defect-containing lithium-doped manganese dioxide-carbon cloth composite by regenerating waste lithium manganese oxide material as described in claim 5, characterized in that... A lithium-doped manganese dioxide-carbon cloth composite with oxygen defects was used as the positive electrode of a zinc-ion battery, a zinc sheet was used as the counter electrode, and 2 mol / L ZnSO4 and 0.2 mol / L MnSO4 were used as electrolytes to assemble a button-type 2025 battery.

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